A pretty neat and free "node montor" is bigbrother

it can monitor diskspace, load, logfiles, connectivity and a lot more if you install 3 party modules..
http://www.bb4.com
is this what you are looking for?

For the sun machines you can also checkout sun's own
hardware monitor :
http://wwws.sun.com/software/solaris...ter/index.html

hope this helps!

/Peter